A vaccine therapy has been proposed in which an immune response to an autoantigen in vivo is positively induced to neutralize the activity of the autoantigen, whereby a disease to which the autoantigen contributes is prevented or treated.
The present inventors have reported that hypertension can be treated well by inducing production of an antibody against angiotensin II, which is achieved by conjugating an angiotensin II-specific epitope with KLH and administering the conjugate (non-patent document 1). Also, the present inventors have found that administration of an expression vector encoding a chimeric hepatitis B virus core antigen polypeptide, wherein an angiotensin II-specific epitope is inserted between amino acid residues 80 and 81 of hepatitis B virus core antigen polypeptide, induces antibody production against angiotensin II and can favorably treat or prevent lifestyle-related diseases such as hypertension and the like (patent document 1). In addition, they have found that administration of an expression vector encoding a chimeric hepatitis B virus core antigen polypeptide, wherein an apolipoprotein (a)-specific epitope is inserted between amino acid residues 80 and 81 of hepatitis B virus core antigen polypeptide, induces antibody production against apolipoprotein (a) while avoiding self-reactive T cell induction and can favorably treat or prevent arteriosclerosis (patent document 2, non-patent document 2). Furthermore, they have found that administration of an expression vector encoding a chimeric hepatitis B virus core antigen polypeptide, wherein a VEGF-specific epitope and/or an angiopoietin-2-specific epitope are/is inserted between amino acid residues 80 and 81 of hepatitis B virus core antigen polypeptide, effectively suppresses tumor angiogenesis, and can treat or prevent cancer (patent document 3, non-patent document 3).
As for DNA vaccine using an expression vector encoding an antigen, it has been reported that boosting by administration of the antigen itself after administration of the DNA vaccine enhances the vaccine effect (non-patent documents 4-7).
However, such effectiveness of these vaccines is not sufficiently satisfactory.